A 5-Ureido-Modified Sialyl Donor: A Tool for the Synthesis of α-Sialosides.

Abstract

A novel method for the synthesis of α-sialosides using a newly developed 5-ureido-modified sialyl donor is reported. The donor was found to be useful for α-selective sialidation with various glycosyl acceptors, forming α(2,6)Glc, α(2,6)Gal, and α(2,3)Gal linkages in excellent yield and with stereoselectivity. Furthermore, α-sialoside was easily isolated from the reaction mixture by the 1,5-lactamization method under mild conditions. Successful application of the C5-ureido sialyl donor to the synthesis of a sialoside confirmed the usefulness of the present method.